Stem cell counting: Development and application

造血系统的干细胞（造血干细胞，hsc）非常罕见，每20000个骨髓细胞中只有1个。因为它们是骨髓中唯一有能力在整个成年期维持血细胞生成的细胞，它们在许多血细胞疾病和大多数白血病中起着核心作用。它们也是骨髓或脐带血移植再生效果的主要治疗实体。因此，有必要能够列举他们在许多实际的临床重要性的情况下。临床HSC移植的结果，例如治疗血液病如白血病，主要取决于供体样本中HSC的数量。不幸的是，目前还没有直接计数造血干细胞的实用方法。相反，需要枚举它们的研究人员必须求助于极其繁琐和昂贵的分析，包括将细胞注射到小鼠体内，然后等待至少5个月才能得到结果。枚举造血干细胞所花费的巨大精力、时间和成本是血液干细胞研究和临床实践的主要限制因素。在此，我们建议开发一种技术，在任何细胞样品中，无论生物状态如何，都可以在半天内直接快速地计数hsc，而无需事先富集。我们的提议汇集了干细胞生物工程（Zandstra），材料和微流体（Kumacheva），干细胞生物学（Iscove）和单细胞细胞术（Audet）领域的多学科世界专家团队。预期的结果将是一个高通量微流体自动化系统（干细胞计数芯片- SCCC），在再生医学和干细胞技术商业化中心的帮助下，该系统将被转化为任何医院都可以使用的设备，用于对罕见细胞类型（如造血干细胞）进行强大的枚举。我们期望SCCC通过提供实时枚举供体样本或患者体内造血干细胞的工具，为干细胞研究和再生医学带来革命性的变化。

The stem cells of the blood-forming system (hematopoietic stem cells, HSCs) are rare, comprising only 1 in every 20,000 bone marrow cells. Because they are the only cell in marrow with the capacity to sustain blood cell production throughout adult life, they play a central role in many blood cell disorders and most leukemias. They are also the principal therapeutic entity responsible for the regenerative effectiveness of marrow or cord blood transplants. There is accordingly a need to be able to enumerate them in many circumstances of practical clinical importance. Outcomes of clinical HSC transplants, for example to treat blood diseases such as leukemia, depend critically on the number of HSCs in the donor sample. Unfortunately, there presently exists no practical means of counting HSCs directly. Instead, researchers that need to enumerate them must resort to extremely cumbersome and expensive assays that involve injecting the cells into mice and then waiting a minimum of 5 months before obtaining a result. The enormous effort, time and cost it takes to enumerate HSCs are major limiting factors in blood stem cell research and clinical practice.We propose here the development of a technology for direct and rapid marker-based enumeration of HSCs within half a day, in any cellular sample regardless of biological state and without requirement for prior enrichment. Our proposal brings together a multidisciplinary team of world experts in the fields of stem cell bioengineering (Zandstra), materials and microfluidics (Kumacheva), stem cell biology (Iscove) and single-cell cytometry (Audet). The anticipated outcome will be a high-throughput microfluidics automatable system (Stem Cell Counting Chip - SCCC) which will be translated, with the help of Centre for the Commercialization of Regenerative Medicine and STEMCELL Technologies, into a device usable in any hospital for the robust enumeration of rare cell types such as HSCs. We expect the SCCC to revolutionize stem cell research and regenerative medicine by providing the tools to enumerate HSCs in donor samples or in patients, in real time.